Add Utility Class for LDAP Security Tool Integration (#12)

primekit-essentials/src/main/java/com/shortthirdman/primekit/essentials/common/util/LDAPUtils.java

@@ -0,0 +1,87 @@
+package com.shortthirdman.primekit.essentials.common.util;
+
+/**
+ * @apiNote Utility class for operations on LDAP
+ * @author shortthirdman
+ * @since 1.0
+ */
+public final class LDAPUtils {
+
+    private LDAPUtils() {}
+
+    /**
+     * Escaping Distinguished Name (DN) to prevent injection attacks.
+     * @param name the DN to escape
+     * @return the escaped DN
+     */
+    public static String escapeDN(String name) {
+        StringBuilder sb = new StringBuilder(); // If using JDK >= 1.5 consider using StringBuilder
+        if ((!name.isEmpty()) && ((name.charAt(0) == ' ') || (name.charAt(0) == '#'))) {
+            sb.append('\\'); // add the leading backslash if needed
+        }
+        for (int i = 0; i < name.length(); i++) {
+            char curChar = name.charAt(i);
+            switch (curChar) {
+                case '\\':
+                    sb.append("\\\\");
+                    break;
+                case ',':
+                    sb.append("\\,");
+                    break;
+                case '+':
+                    sb.append("\\+");
+                    break;
+                case '"':
+                    sb.append("\\\"");
+                    break;
+                case '<':
+                    sb.append("\\<");
+                    break;
+                case '>':
+                    sb.append("\\>");
+                    break;
+                case ';':
+                    sb.append("\\;");
+                    break;
+                default:
+                    sb.append(curChar);
+            }
+        }
+        if ((name.length() > 1) && (name.charAt(name.length() - 1) == ' ')) {
+            sb.insert(sb.length() - 1, '\\'); // add the trailing backslash if needed
+        }
+        return sb.toString();
+    }
+
+    /**
+     * Escaping search filter to prevent injection attacks.
+     * @param filter the search filter to escape
+     * @return the escaped string form of search-filter
+     */
+    public static String escapeSearchFilter(String filter) {
+        StringBuffer sb = new StringBuffer(); // If using JDK >= 1.5 consider using StringBuilder
+        for (int i = 0; i < filter.length(); i++) {
+            char curChar = filter.charAt(i);
+            switch (curChar) {
+                case '\\':
+                    sb.append("\\5c");
+                    break;
+                case '*':
+                    sb.append("\\2a");
+                    break;
+                case '(':
+                    sb.append("\\28");
+                    break;
+                case ')':
+                    sb.append("\\29");
+                    break;
+                case '\u0000':
+                    sb.append("\\00");
+                    break;
+                default:
+                    sb.append(curChar);
+            }
+        }
+        return sb.toString();
+    }
+}

primekit-essentials/src/test/java/com/shortthirdman/primekit/essentials/common/util/LDAPUtilsTest.java

@@ -0,0 +1,24 @@
+package com.shortthirdman.primekit.essentials.common.util;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class LDAPUtilsTest {
+
+    @Test
+    void escapeDN() {
+        assertEquals("No special characters to escape", "Helloé", LDAPUtils.escapeDN("Helloé"));
+        assertEquals("leading #", "\\# Helloé", LDAPUtils.escapeDN("# Helloé"));
+        assertEquals("leading space", "\\ Helloé", LDAPUtils.escapeDN(" Helloé"));
+        assertEquals("trailing space", "Helloé\\ ", LDAPUtils.escapeDN("Helloé "));
+        assertEquals("only 3 spaces", "\\  \\ ", LDAPUtils.escapeDN("   "));
+        assertEquals("Christmas Tree DN", "\\ Hello\\\\ \\+ \\, \\\"World\\\" \\;\\ ", LDAPUtils.escapeDN(" Hello\\ + , \"World\" ; "));
+    }
+
+    @Test
+    void escapeSearchFilter() {
+        assertEquals("No special characters to escape", "Hi This is a test #çà", LDAPUtils.escapeSearchFilter("Hi This is a test #çà"));
+        assertEquals("LDAP Christams Tree", "Hi \\28This\\29 = is \\2a a \\5c test # ç à ô", LDAPUtils.escapeSearchFilter("Hi (This) = is * a \\ test # ç à ô"));
+    }
+}